四溴代对苯二甲酸根桥联的双核钴（Ⅱ）配合物的合成和表征

SYNTHESIS AND MAGNETISM OF TETRABROMOTEREPHTHALATO BIDGED COBALT(Ⅱ) BINUCLEAR COMPLEXES

文报道了四种新的双核钴（Ⅱ）配合物，即［Ｃｏ２（４Ｂｒ－ＴＰＨＡ）（Ｌ）４］（ＣｌＯ４）（４Ｂｒ－ＴＰＨＡ＝四溴代对苯二甲酸根阴离子，Ｌ＝１，１０－菲咯啉（ｐｈｅｎ）（１），５－硝基－１，１０－菲咯啉（ＮＯ２－ｐｈｅｎ）（２），２，２′－联吡啶（ｂｐｙ）（３）和４，４′－二甲基－２，２′－联吡啶（Ｍｅ２ｂｐｙ）（４））的合成和表征，基于ＩＲ光谱、元素分析、电导测量等方法推定配合物具有四溴代对苯二甲酸根桥联结构和Ｃｏ（Ⅱ）离子具有畸变的八面体配位环境，配合物的变温磁化率（７５－３００Ｋ）已测，其数据已用从自旋哈密顿算符Ｈ＝－２ＪＳ１·Ｓ２导出的磁方程拟合，求得交换参数为Ｊ＝－０．８８ｃｍ－１（１），Ｊ＝－０．８６ｃｍ－１（２），Ｊ＝－０．８９ｃｍ－１（３），Ｊ＝－０．９０ｃｍ－１（４），表明金属离子间有弱的反铁磁性自旋变换相互作用。

Four Novel Cobalt(Ⅱ) complexes have been synthesized and characterized,namely [Co 2(4Br-TPHA)(L) 4](ClO 4) 2 (L denotes 1,10-phenanthroline(phen) (1),5-nitro-1,10-phenanthroline(NO 2-phen) (2),2,2′-bipyridyl(bpy) (3) and 4,4′-dimethyl-2,2′-bipyridyl (Me 2bpy) (4),respectively),where 4Br-TPHA is the tetrabromoterephthalate dianion,Based on IR,elemental analyses and conductivity measurements,these complexes and proposed to have extended tetrabromoterephthalato-bridged structure consisting of two cobalt ions in which each cobalt(Ⅱ) ion has a distorted octahedral environment.The temperature dependance of the magnetic susceptibility for all the complexes were measured over the range 75-300K and the observed data were successfully simulated by an equation based on the spin Hamiltonian operator ( =-2J 1· 2 ),giving the exchange integral J =-0.88cm -1 (1), J =-0.86cm -1 (2), J =-0.89cm -1 (3), J =-0.90cm -1 (4).These results indicate weak antiferromagnetic spin exchange interaction between the metal ions.